• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.1
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• pp.130-136
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• 2008

This paper describes a low-power high-performance analog front-end block for $UHF(860{\sim}960MHz)$ band RFID tag chips. It satisfies ISO/IEC 18000-6 type C(EPCgolbal class1. generation2.) and includes a memory block for test. For reducing power consumption, it operates with a internally generated power supply of 1V. An ASK demodulator using a current-mode schmitt trigger is proposed and designed. The proposed demodulator has an error rate as low as 0.014%. It is designed using a 0.18um CMOS technology. The simulation results show that the designed circuit can operate properly with an input as low as $0.2V_{peak}$ and consumes $2.63{\mu}A$. The chip size is $0.12mm^2$

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.10
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• pp.59-65
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• 2008

We have proposed a UHF/HF multi-band RFID reader, and have implemented it into a system in a package(SiP). The proposed SiP RFID reader has been designed to support both for EPCgloabal Class1 Generation2 protocol of UHF band, and 13.56MHz RFID protocols of ISO14443 A/B type, and ISO15693 standards. The operating mode is controlled by embedded RISC core, and the mode can be selected by users. The area of implemented SiP is $40mm{\times}40mm$ with 4 metal layers. The implemented reader SiP operates at single supply voltage of 3.3V. The maximum current consumption is 210mA. The operating distances are 5cm for 13.56MHz modes, and 20cm for UHF mode.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.6
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• pp.74-80
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• 2008

Analysis of the electromagnetic environment on topside of a ship is needed for optimal arrangement of all kinds of antennas to be installed on the shipboard in order to minimize the probability of EMI of equipment and subsystems in real ship after construction phase. In this paper we analyze the characteristics of electric-fields such as radiation patterns and near E-fields of V/UHF antennas installed on a shipboard. We compare simulated results with measurements on the real ship for near E-fields to verify the reliability of the computed electromagnetic environment. Although there are various factors causing errors such as cable loss and impedance mismatching etc. when measuring near E-field, both data show similar trends in the range of the acceptable tolerance.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.1 s.24
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• pp.33-40
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• 2006

A compact broadband active composite dipole antenna for direction finding system at the V/UHF-band is presented. It uses the composite structure which improves the antenna gain and the active circuit for broadband operation. This type of antenna has a high gain more than that of one dipole antenna within limited length(1m). The basic design and performance of both antenna structure and integrated active circuit are presented.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.2
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• pp.302-312
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• 2012

In this paper, small-area and high-reliability design techniques of a 512-bit EEPROM are designed for UHF RFID tag chips. For a small-area technique, there are a WL driver circuit simplifying its decoding logic and a VREF generator using a resistor divider instead of a BGR. The layout size of the designed 512-bit EEPROM IP with MagnaChip's $0.18{\mu}m$ EEPROM is $59.465{\mu}m{\times}366.76{\mu}m$ which is 16.7% smaller than the conventional counterpart. Also, we solve a problem of breaking 5V devices by keeping VDDP voltage constant since a boosted output from a DC-DC converter is made discharge to the common ground VSS instead of VDDP (=3.15V) in getting out of the write mode.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.2
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• pp.333-338
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• 2008

In this paper, a new NMOS current-mirror type bridge rectifier for driving RFID chips, whose minimum input voltage required to obtain the effective DC output voltage is low enough and whose power dissipation can be reduced than that of conventional one, is proposed. The designed rectifier is able to supply high enough and well-rectified DC voltages to drive RFID transponder chips for the frequency range of 13.56 MHz HF(for ISO 18000-3), 915 MHz UHF(fur ISO 18000-6), and 2.45 GHz microwave(for ISO 18000-4). Output characteristics of the proposed rectifier are analyzed with the high frequency equivalent circuit. And the circuitry method for effective reducing of the gate leakage current due to the increasing of operating frequency is also proposed theoretically. Using this method, the power consumption of $100\;{\mu}W$ and the DC output voltage of 2.13V for 3V peak-to-peak input voltage and $45\;K{\Omega}$ load resistance are obtained. Compared to conventional one, the proposed rectifier operates in more stable and shows superior characteristics in UHF and microwave frequencies.

• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.37-39
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• 2002

UHF method is very effective to diagnosis for partial discharge of GIS. In generally, inner UHF sensor can be attached on sheath cover of GIS under construction for periodic inspection. However, there is no inner UHF sensor for GIS of the domestic substation. We used the outer UHF sensor attached on spacer for GIS of existing substation. In this paper, we report the diagnosis result of partial discharge on 800kV GIS in domestic substation. From these results, we can find the quantity, reason and location of PD and certificate the performance of UHF method for partial discharge diagnosis of GIS.

• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.525-527
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• 2000

Ultra high frequency (UHF) signals caused by the bouncing motion of aluminium particles in the 352 kV gas-insulated switchgear (GIS) test chamber were measured in order to investigate the signal pattern against the applied voltage phase and ultra sonic signals.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2290-2292
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• 1999

The Ultra-High Frequency(UHF) method for detecting a partial discharge in Gas-Insulated Substation(GIS) has some advantages compared to a conventional method(IEC 270) but there is a shortage in view of a quantitative analysis. Therefore, this paper describes the implementation of a calibrator and the calibration process based on it. And its characteristics are confirmed through the experiment using the 362kV GIS chamber.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.7 s.361
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• pp.9-15
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• 2007

In this paper, we present the design of Schottky diodes and voltage multiplier for UHF-band passive RFID applications. The Schottky diodes were fabricated using Titanium (Ti/Al/Ta/Al)-Silicon (n-type) junction in $0.35\;{\mu}m$ CMOS process. The Schottky diode having $4{\times}10{\times}10\;{\mu}m^{2}$ contact area showed a turn-on voltage of about 150 mV for the forward diode current of $20\;{\mu}A$. The breakdown voltage is about -9 V, which provides sufficient peak inverse voltage necessary for the voltage multiplier in the RFID tag chip. The effect of the size of Schottky diode on the turn-on voltage and the input impedance at 900 MHz was investigated using small-signal equivalent model. Also, the effect or qualify factor of the diode on the input voltage to the tag chip is examined, which indicates that high qualify factor Schottky diode is desirable to minimize loss. The fabricated voltage multiplier resulted in a output voltage of more than 1.3 V for the input RF signal of 200mV, which is suitable for long-range RFID applications.